Occurrence and control of seed borne fungi of four food crops in Sudan

Abstract

The present study was plant pathology laboratory conditions of Plant Protection Department, College of Agricultural Studies, Sudan University of Science and Technology to investigate the occurrence of seed-borne fungi on sorghum, pearl millet, groundnut and sesame seeds collected from four different locations, each in one state of Sudan(Gazera , Gadarif, Elobid , and Niyalla) and their possible control using aqueous plant extracts (Garlic Neem, Argel, Damas and Tilt fungicide at (100%,50%,25% ) respectively . Out of the 16 seed samples, 4 of each crop, tested for seed borne fungi, a total of eleven genera of twelve species of fungi were recorded. The seed borne fungi recorded were Penicillium digitatum, , Aspergillus niger, Rhizopus nigricans, Drechslera spicifera, Alternaria solani, Fusarium solani, Colletotricum graminicola, Rhizoctonia solani, Phoma glomerata, Curvularia lunata , Macrophomina phaseolina and Aspergillus flavus with mean percent incidence ranging from (23%-16% – 12%-8.0%-10%-4.0%-6.0%-2.0%- 2.0%-2.3%-2.5%-2.3%and 53%) respectively . The higher percent incidence was recorded by Aspergillus flavus (53%) in sesame calculated by used rule (infected seeds –healthy seeds)100 . The four most prevailing seed borne fungi recorded across crops seeds were Penicillium digitatum, Aspergillus flavus, Aspergillus Niger, and Rhizopus nigricans with varying level of incidences. Likewise, all concentrations of the leaves aqueous extracts of all plants tested and fungicide ( Tilt –Garlic- Argel- Neem , , and Damas) ranging from (100%,50%,25% respectively ) exhibited significantly high inhibitory effect against the linear growth of test fungus(93.8-100-100,27.2- 91.3-100,66.0-73.8-84.1,23.8-54.9-66.7,13.3-21.9-31.1) as well at all concentrations gave the highest inhibition zones percent compared to control. Moreover, concentrations of each aqueous extract as well as that of fungicide reacted differently against test fungus. However, among plant extracts the Garlic at all concentrations tested (25, 50 and 100%) exhibited consistently XI the highest inhibitory effect throughout the days (three ,four and five respectively in Table 1,2,and,3 of experiments (100%,100%,46.1% , 100%,100%,90.4% and 100%,100%,93.8%) than the other equivalents. Similar effect was also demonstrated by the fungicide (100%, 100%, 94.5%; 100%, 100%, 94%; 100%, 100%, 100%) throughout that days respectively. However, the inhibitory effect of Damas Leave Aqueous extracts (100%, 50%, 25%) respectively gave lowers inhibitory effect that was (70%, 42.2%, 18.5%; 63.5%, 50.6% 48.3%; and 31.1%, 21.9%66%) reduced with time of recording. Generally, the results showed that the antifungal activity increase with extract concentration. However the Garlic Extract gave highest effect of fungus compared to Damas aqueous extract and similar effect of fungicide. Obviously, the test fungus differs in its response to the different concentrations but on the whole, growth inhibition increased with the concentration. The findings of this study are therefore, important as they highlighted the need for adhering to effective measures that aimed at reducing seed-borne fungi incidence in stable food crops seeds in Sudan.